Adequate visualization has posed a challenge in the exploration and treatment of internal areas of the human body. Visualization may be especially troublesome in minimally invasive procedures in which small diameter, elongate instruments, such as catheters or endoscopes, may be navigated through natural passageways and cavities of a patient to a region of interest (work site).
In conventional minimally invasive procedures, an endoscope or catheter may be inserted into the body for diagnostic or therapeutic purposes. A distal end of an endoscope may be inserted into the body through an opening in the body. This opening may be a natural anatomic opening, such as, for example, the mouth, rectum, vagina, etc., or an incision made on the body. The endoscope may be pushed into the body such that the distal end of the endoscope proceeds from the point of insertion to a work site within the body by traversing a body lumen, for example, the gastric, pulmonary, esophageal, or urological tracts.
Once inside the body, performing diagnostic and treatment procedures requires sufficiently clear visualization. Navigating and identifying regions of interest may require down-lumen visualization. For down-lumen visualization, high-intensity light with a small spot size may be directed towards the center of a body lumen. When directed towards near-field objects, however, this light may become saturating and image details may be lost. By contrast, visualizing the near-field lumen periphery may require wide-angle, low-intensity light. While such low-intensity light avoids saturation of near-field objects, it may not provide enough illumination to visualize down lumen. These variations in illumination requirements may make navigation and visualization of the work site difficult, potentially increasing procedure time and decreasing accuracy, and thus increasing the possibility of complications for the patient.
Conventional endoscopes may utilize complex and/or expensive systems, such as arrays of optical fibers or light-emitting diodes (“LEDs”) at a distal region of an endoscope in order to provide uniform illumination in both the near and far fields. But such devices may increase the size of endoscopes, making them cumbersome to maneuver and restricting the cavities through which they may pass. Additionally, they may increase the cost of manufacturing and maintaining these instruments.
Accordingly, a need exists for a compact, cost-effective visualization unit capable of achieving adequate uniform far-field and near-field illumination. The medical devices and related methods of the present disclosure are directed to improvements in the existing technology and overcome at least some of the deficiencies in the prior art.